Increasing the strength of iridium, rhodium, and alloys thereof

Abstract

The addition of 0.5 to 30 ppm boron and 0.5 to 20 ppm calcium to iridium and the Zr- and Hf-free alloys thereof and rhodium and the Zr- and Hf-free alloys thereof surprisingly increases the creep rupture strength at high temperatures, in particular around 1,800° C.

We claim: 
     
       1. A method for increasing creep rupture strength of iridium metal, the method comprising adding 0.5 to 30 ppm boron and 0.5 to 20 ppm calcium by weight to pure iridium metal to produce doped iridium, wherein the doped iridium consists of iridium, calcium, and boron, and wherein the creep rupture strength of the doped iridium is 20 to 30% higher than that of the pure iridium metal.